重现死锁，数据库或程序代码类似

//方式一，写交替死锁，Test1，Test2不会被输出
using System.Threading;
using System;

public static class Program
{
    static object obj1 = new object();
    static object obj2 = new object();

    static void Main()
    {
        Thread thread1 = new Thread(Test1);
        Thread thread2 = new Thread(Test2);
        thread1.Start();
        thread2.Start();

        Console.WriteLine("Run");
        Thread.Sleep(int.MaxValue);
    }
    static void Test1()
    {
        lock (obj1)//update obj1 set a=1 where id=1;
        {
            Thread.Sleep(100);
            lock (obj2)//update obj2 set b=1 where id=1;
            {
                Thread.Sleep(100);
            }
        }
        Console.WriteLine("Test1");
    }
    static void Test2()
    {
        lock (obj2)//update obj2 set b=1 where id=1;
        {
            Thread.Sleep(100);
            lock (obj1)//update obj1 set a=1 where id=1;
            {
                Thread.Sleep(100);
            }
        }
        Console.WriteLine("Test2");
    }
}
//方式二，读写交替死锁，Test1，Test2不会被输出
using System.Threading;
using System;

public static class Program
{
    static ReaderWriterLock lock1 = new ReaderWriterLock();
    static ReaderWriterLock lock2 = new ReaderWriterLock();

    static void Main()
    {
        Thread thread1 = new Thread(Test1);
        Thread thread2 = new Thread(Test2);
        thread1.Start();
        thread2.Start();

        Console.WriteLine("Run");
        Thread.Sleep(int.MaxValue);
    }
    static void Test1()
    {
        lock1.AcquireReaderLock(-1);//select a from obj1 where id=1;
        Thread.Sleep(100);

        lock2.AcquireWriterLock(-1);//update obj2 set b=1 where id=1; 
        Thread.Sleep(100);
        lock2.ReleaseWriterLock();

        lock1.ReleaseReaderLock();

        Console.WriteLine("Test1");
    }
    static void Test2()
    {
        lock2.AcquireReaderLock(-1);//select b from obj2 where id=1;
        Thread.Sleep(100);

        lock1.AcquireWriterLock(-1);//update obj1 set a=1 where id=1;
        Thread.Sleep(100);
        lock1.ReleaseWriterLock();

        lock2.ReleaseReaderLock();

        Console.WriteLine("Test2");
    }
}